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Section 1 — General Information
HTS “Wn” Type Transfer Switch
1.1 INTRODUCTION
This manual has been prepared especially for the purpose of famil-
iarizing personnel with the design, application, installation, opera-
tion and servicing of the applicable equipment. Read the manual
carefully and comply with all instructions. This will help to prevent
accidents or damage to equipment that might otherwise be caused
by carelessness, incorrect application, or improper procedures.
Every effort has been expended to make sure that the contents
of this manual are both accurate and current. The manufacturer
reserves the right to change, alter or otherwise improve the prod-
uct at any time without prior notice.
1.2 EQUIPMENT DESCRIPTION
The commercial transfer switch range (HTS) is designed to oper-
ate in conjunction with the Power Manager Gxxx and Hxxx series
of Generator controllers. The transfer switch has a simple 2-wire
communications link to the Generator controller and can thus be
mounted remote from the Generator.
Utility voltage is monitored by the HTS and fed back to the engine
generator control panel for comparison against setpoints, used to
determine if the Utility voltage is "good".
Operation of the switch is instigated by the generator control
panel, however, all aspects of TDN timing or inphase transfer are
handled locally at the HTS. The HTS monitors a single phase of the
Generator voltage in order to perform inphase transfers.
All timers and voltage setpoints are programmable in the G/H
control panel. Some of the decisions are made by the HTS itself
so the appropriate parameters are passed to the HTS via the com-
munication link. If the communication link were to break, the HTS
will still function. It will monitor the Utility and Generator voltages
and make the transfer determination itself, rather than being com-
manded by the generator control panel. It will either use the last
parameters sent, or, if no parameters were ever sent (communica-
tions were never established), it will take its settings from onboard
DIP Switches and a set of resident parameters.
The automatic transfer switch is used for transferring critical elec-
trical load from a NORMAL (UTILITY) power source to a STANDBY
(EMERGENCY) power source. Such a transfer of electrical loads
occurs automatically when the NORMAL power source has failed
or is substantially reduced and the STANDBY source voltage and
frequency have reached an acceptable level. The transfer switch
prevents electrical feedback between two different power sources
(such as the NORMAL and STANDBY sources) and, for that rea-
son, codes require it in all standby electric system installations.
1.3 TRANSIENT VOLTAGE SURGE
SUPPRESSION
The Transient Voltage Surge Suppression (TVSS) is provided to
protect the load from electrical surges and/or transient voltage
spikes. This device is physically located on the side wall of the
enclosure. It is electrically connected to the load side of the trans-
fer switch. A 30 amp circuit breaker is provided to disconnect the
TVSS from the transfer switch for maintenance or replacement.
The TVSS is made up of multiple solid state Metal Oxide Varistors
(MOV) connected in parallel for each mode of protection. These
devices are equipped with integrated short circuit and individual
component level fusing. They are self-resetting and fully auto-
matic.
1.3.1 MODES OF PROTECTION
The TVSS provides protection on all modes:
Single-phase (6) - L-L, L-N, L-N, L-G, L-G and N-G.•
Three-phase (10) - L-L, L-L, L-L, L-N, L-N, L-N, •
L-G, L-G, L-G and N-G.
1.3.2 RATINGS
Surge Capacity: 88 kA per mode.•
1.3.3 CERTIFICATION
The TVSS is UL recognized to the requirements of UL 1449 2nd
edition.
1.3.4 TVSS DISCONNECT
Each TVSS is provided with a disconnect. The disconnect is a 30
amp circuit breaker, 2-pole for single-phase and 3-pole for three-
phase. This is to allow replacement of the TVSS module without
interruption of the electrical supply to the load.
DANGER
REPLACEMENT OF THE TVSS MODULE WHILE
THE ATS IS ENERGIZED SHOULD ONLY BE
PERFORMED BY A QUALIFIED ELECTRICIAN.
BE SURE TO TURN ON TVSS DISCONNECT
CIRCUIT BREAKER WHEN THE PROCEDURE IS
COMPLETE. IF THE CIRCUIT BREAKER IS NOT
TURNED ON THE TVSS MODULE WILL NOT
PROVIDE ANY SURGE PROTECTION FOR THE
CUSTOMER LOAD.
1.3.5 STATUS INDICATORS
Each TVSS module has comprehensive, solid state, continual
visual status monitoring of each protection mode present. There
are two LED’s provided, located on the cover of the module. The
GREEN LED (left side) is used to indicate that the TVSS module is
energized and in working order. The RED LED (right side) will turn
on in the event the suppressor capability is exceeded or if there is
an internal safety component activating.
When the power is first applied, the unit does a brief internal diag-
nostic test. During this test, the RED LED will illuminate briefly, go
off and then the GREEN LED will illuminate.